Protesters at the Republican National Convention were detained for hours on an oil-soaked, asbestos-filled pier that they say was never fully cleaned up by the Transit Authority, a city lawmaker claims.

Councilmember Margarita Lopez (D-East Village) and several of her colleagues and protesters, who say they were illegally detained on Pier 57 for 48 hours, called for an investigation about city use of the pier during the convention.

But a TA spokesman said the pier had been cleaned before it was turned over to the Hudson River Park Trust.